Fix null cursor field in RPC
Fix null cursor field in RPC

- resolves #200

modelorganism/xi-editor,modelorganism/xi-editor,google/xi-editor,modelorganism/xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,google/xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,fuchsia-mirror/third_party-xi-editor,fuchsia-mirror/third_party-xi-editor